Transmitter for the deaf.



H. TIDEMAN.

TRANSMITTER FOR TH]; DEAF. APPLICATION FILED JUNE-11, 1909.

2 SHEETS-SHEET 1.

Wmuzsses; i NVENTORZ HENRY TIDEMAN ATTvs.

' Patented Aug. 27, 1912.

H. TIDEMAN. TRANSMITTER FOR THE DEAF.

' APPLICATION FILED JUNE 11, 1909.

1,036,933, Patented Aug. 27, 1912.

2 SHEETS-SHEET 2.

x lulllllllllly.iiiiiill\\ I R illllmmlmll\IIHIIIIIIHIIINIW WITNESSES. INVENTOR:

I I HENRY TIDEMAN WNW B QZ 7MQ TTYSI -HENRY TIDEMAN, F M ENOMINEE, MICHIGAN. I

TRANSMITTER FOR THE Dean osaess.

Specification of Letters Patent.

Patented Aug.27,1912.

Application filed June 11, 1969. Serial'No. 501,495.

1 To all whom it may concern:

Be it known that I, HENRY TIDEMAN, a citizen of the United States of America, and

' a resident of Menominee, county of Menominee, and State ofMichigan, have invented a new and useful Improvement in Transmitters for the Deaf, of which the following is a specification.

.My invention pertains to electrical speechtransmitting devices of design suitable for collecting sounds from any distance. and transmitting electrical waves as controlled thereby, particularly to types designed to be carried upon the person and forming parts of systems for assisting'the hearing of persons having this sense impaired.

In telephone transmitters of the carbon type, whether of the granular carbon structure or of some other design, difficulty is encountered in producing a universal instrument which will be adapted without specific adjustment to sounds either strong or weak and located either ,near or distant from the transmitter, or located either directly in front or at a considerable angle from the front of the transmitter. The transmitter adapted to receive and interpret electrically sounds which are minute in volume will be found to blare when the sound waves. impinge upon its diaphragm with too great energy. Such atransmitter is found in the old Blake instrument, mounted in its wood box. On. the other hand, instruments so constructed mechanically as to withstand rigorous conditions of sound waves upon their diaphragms usually are insensitive to the waves of smaller volume and to the finer modulations of the voice waves. The structure of my invention operates to equalize upon the diaphragm the sound waves re? ceived by the instrument, to preventthe blaring of the instrument under violent sound action and to render itv insensitive to minute sound waves which may reach it.

With a given distance from .the speakers lips to the telephone transmitter, the eflective energy of the sound waves, where a transmitter of ordinary constructlon is considered, varies. with the change in the angle between the line normal to the transmitter diaphragm, and, a line from the center of the diaphragm to the speakers lips. When'the speaker is in line with the normal of the diaphragm, the sound waves of his speech are most eflective in operating the transmitter. When he speaks to the transmitter from a considerable'angle, say 40 or degrees, his speech has but a small fraction of its normal efficiency. I equalize this variation by a system of reflecting and obstructing means in my improved transmitter.

A transmitting resistance constructed and adjusted to appreciate minute sound waves has been impracticable for general use by reason of the blare resulting when the trans mitter is spoken into directly. I make possible the successful use in practice of a transmitting mechanism so designed and constructed as to respond to smaller sound waves, my device for so doing consisting first of obstructing features whereby speech directed too strongly into the transmitter will be held subdued to a volume suited to the verysensitive transmitters and consisting further of reflecting surfaces and conducting channels whereby sound Waves proceeding from considerable angles are permitted to reach .the diaphragm without loss of efiicienoy and to produce a response in the transmitter.

The transmitter, constructed in accordance with the principles above out-lined, is responsive to sounds arising within a wide angular range. This feature, at times very desirable, is at other times somewhat objectionable, since an aillicted person may desire to concentrate the sound. collecting abilities of his transmitter upon the voice of a single person rather than upon the utterances of all of aniassembled company. To supply this requirement of a transmitter, I provide an auxiliary device or attachment which 1 term a concentrator. This device has the effectof rendering the transmitter responsive only to sounds arising within a smaller angle and makes the transmitter more fully responsive to sounds arising within the more limited angle. The ooncentrator I prefer to make in the form of an attachment which may be placed upon the transmitter or removed therefrom at will,

although, of course, it may be built integrally with the transmitter, if so desired.

My improved transmitter comprises a chamber containing a very sensitive car ilt) holesnear the edge. Within the chamber are two truncated cones of sheet metal, one within the other, and both tapering from the front wall of the chamber. The outer of these cones reflects from its inner surface, and the inner refl cts both from the outer and inner surfaces. Sounds entering from considerable angles are passed by the reflections of the cones to the diaphragm, the paths being such as to cause the sound waves to impinge upon the diaphragm at angles less inclined to the ve tic'al than the original direction of the soufid waves, thereby increasing the effect upon the diaphragm of the diagonal sound waves which ordinarily are less effective upon the transmitter. After two reflections, or any even number of reflections from parallel surfaces, sound has again its original directi0n,3but where the surfaces are not parallel, the ultimate direction of the sound is changed. To secure this effect as an advantage in my improved transmitter, I make the reflecting cones of different degrees of inclination to their axes, the outer cone having'the greater inclination to its axis.

The transmission of sounds received diagonally is principally through the large .holes in the face of the transmitter near the periphery. When my concentrator is applied to the front of my transmitter, the effect of the large outside holes in the transmission of sounds from wide angles is greatly reduced, as sounds reaching those openings must do so through the ring of holes in the faceof the concentrator near the periphery. The angleof the sounds'which may reach, the diaphragm by this path is much smaller than the angle accommodated without a concentrator. In addition" the sounds from directly in front are passed through the outer openings of the concentrator and the outer openings of the transmitter face plate, and thence to the dim phragmf i The following drawings, in which like labels refer to like parts throughout, accompany and form a part of these specifications.

Figure 1 shows front view ofmy assembled transmitter and concentrator. 'Fig. 2

shows sectional view of, same on the line 2-2 of Fig. 1. Fig. 3 shows side view of same. Fig. 4 shows front view of my im-. proved transmitter with the concentrator removed. Fig. 5 shows section of my improved transmitter alone, indicating the .handling of sounds received from diiferent directions. Fig. 6 shows section of my improved transmitter and concentrator, and shows the-handling of sound received from different directions.

In Fig. 5, lines 32, a3, 34 and 35 Show the. action of the reflecting surfaces of the transmitter upon sound passing through the openings of the face plate in a direction surfaces. Line 8st through opening 8 is turned back upon itself. Line 35 through the central opening 8 is passed without obstruction -to the diaphragm 4'. The diagonal line 31, however, is reflected by part 6 and then by part 5 and reaches the diaphragm 4' in a direction more nearly perpendicular to the plane of the diaphragm. Line 31 is about the maximum of diagonal line showing the angle at which sound may reach the transmitter and be carried effectively to the diaphragm 4.

In Fig. 6, the lines i3, 45 and 47 show the action of the device upon sound perpendicularly related to the diaphragm. The line 47 through opening 13 proceeds uninterruptedly to the-diaphragm Diagonal lines 44 and 46 through openings 13 and 13 also pass uninterruptedly to the diaphragm. \Diagonal line 42 is doubly reflected and shows the change in angle which is provided for "in my invention, the line 42 after reflection being more:nearly perpendicular to the diaphragm than before reflection. Line 41 is about -the maximum of diagonal line showing the angle at which ound may reach the transmitter diaphragm through the concentrator efficiently.

The transmitter case consists of .front plate 1, having-the annular edge 2 forming a box-like receptacle. This is closed by back plate 3. On the back plate 3 is mounted the transmitter cell 4:, which may be of any design responsive to minute sound waves and minutevoice inflections but which I prefer to make in accordance with general principles and details set forth in myapplication for United States Patent No. 453,350; filed September 16, 1908, for telephone transmitter.

To the face plate 1 is secured. the inner cone 5, and between the face plate 1 and the rigid metallic case of the transmitter 4 is clamped the sheet metal reflecting truncated cone6.. The location of the large openings is indicated in Fig. 2 upon dotted lines at 7. The central openings 8 lie within the inner truncated reflecting cone.

My concentrator comprises a face plate 10, and an annular portion 11 mechanically united. Upon the inside of face plate 10 is secured the truncated cone 12. A system of smaller perforations 13 is located within the truncated cone, and a system of larger pen forations 14 is located in the face plate outside of the cone.

The annular portion 20f the transmitter is provided with rib-like feet 2, 2, and with an upper lug .2, which carries terminals 10 for the leading-in conductors. An-

nular portion 11 ofthe concentrator is of proper size to slip close'lyover the cylindrical transmitter case and is so conformed on its edges as to engage projections 2, 2', and 2" to determine its proper position upon the transmitter case. I

I do not wish to limit my invention to the specific structure herein described and illustrated. I i

What I claim as new. and desire to secure by United States Letters Patent is:

1. In a transmitter, a sound responsive resistance cell, and a set of concentric conical .reflecting surfaces, each a' truncated cone tapering toward said resistance element.

2. In a transmitter, a sound. responsive resistance .cell, and a set of concentric conical reflecting surfaces, each a truncated cone tapering toward said resistance element, said reflecting surfaces being coaxial and having their axes normal to the sound receiving diaphragm of saidsound responsive device. I j

3. In a transmitter, a case comprising front and back plates; sound responsive apparatus mounted rigidly upon said back plate; and aset of sound reflecting truncated cones within said transmitter case, and

positioned between said front plate and the sound responsive device.

4.111 a transmitter, a case comprising a front plate and a back plate; a transmitter cell mounted upon said back plate rigidly; and a set of sound receiving cones engaging said front plateand said transmitter cell, and clamped between them.

5. In atransmitter, a perforated front plate; a sound responsive cell mounted in the rear thereof and two truncated cones between said front plate and said transmitter; said front plate having two systems of perforations, one system within the base of the inner cone, and the other system betweenthe inner and outer cone.

6. In a'transmitter, a sound receiving diaphragm; a case inclosing said diaphragm, said case having-two systems of apertures; reflecting surfaces cooperating with said apertures to conduct diagonally received sound waves into impingement with said diaphragm more eflici ently than normally received sound waves. 7

7. In a transmitter, two coaxial reflecting conical surfaces, the outer of which has a greater inclination to its axis than the inner.

8. In a transmitter, two coaxial truncated reflecting conical surfaces, the outer of which has a greater inclination to its axis than the inner.

9. 'In a transmitter, a concentrator, 'comprising a face plate and a set of concentric. truncated cones attached to the inner surface thereof.

10. In a transmitter, a concentrator comprising a face plate perforated with two systemsof holes; and a truncated cone tached to the inner surface of the face plate, said two systems of holes being disposed,

one system within the base of said cone and the other surrounding the base of said cone.

'11. In a transmitter, a transmitter case having projections adapted to form a base, for supporting the transmitter case and a projection forming a mounting place for terminals;.'a concentrator having a flange adapted to surround said transmitter-case, the edges of said flange being cut to take seat against the projections of said case to determine the relative position of the concentrator upon the transmitter case.

12. In a transmitter, a series of two perforated face plates, each carrying reflecting cones; and a sound receiving diaphragm, mounted parallel to said face plates and perpendicular to the axis of said cones.

13. In a transmitter, a series of two perforated face plates, each carrying reflecting cones; and a sound receiving diaphragm, mounted parallel to said face plates and perpendicularly to the axis of said cones,

each of said face plates being perforated in side and outside of its central reflecting cone and all of said reflecting cones tapering toward said sound receiving device.

14. A sound concentrator comprising a vibratory diaphragm, a frusto-conical deflector located in front-of said diaphragm with its smaller end terminating in front of and adjacent thereto and a relatively small deflector concentrically located within said frusto-co'nical deflector with its smaller end also adjacent to said diaphragm. 15. A sound concentrator comprising a 'case, a diaphragm supported within and 'ad depth. as said frusto-conical deflector but of relatively small maximum diameter, the lines of both deflecting surfaces being con.- vergent inwardly.

17. A- transmitter comprising a metal case, a diaphragm mounted upon the base of said case, two' concentric conicaldefle'ctors projecting into-said case fromits forward end and having inwardly. converging surfaces that terminate adjacent to said diaphragm, and means for impartingthe vibratoryinfluence of said diaphragm to an electric circuit.

18. A sound transmitter comprising a cylindrica-l case having an open front end, a Signed by me at Menominee, county of vibratory diaphragm sup-ported Within said i Menominee and State of Michi an, in the case, and means for directing'and deflecting i presence oftwo witnesses.

forwardly against the central part of said HENRY TIDEMAN.

diaphragm all of the sound WiLVfiS inter- \Vitnesscs: I cepted by said open end that do not impinge LECPOLD J AGKMAN, disectly against said central part. F'nuNcIs J. DONOVAN.

Copies of this patent may be obtained for five cents each, by addressing the Coinmissioner of Patents,

- Washington, D. G." 

